http.c

   1 #include "git-compat-util.h"
   2 #include "http.h"
   3 #include "pack.h"
   4 #include "sideband.h"
   5 #include "run-command.h"
   6 #include "url.h"
   7 #include "urlmatch.h"
   8 #include "credential.h"
   9 #include "version.h"
  10 #include "pkt-line.h"
  11 #include "gettext.h"
  12 #include "transport.h"
  13
  14 #if LIBCURL_VERSION_NUM >= 0x070a08
  15 long int git_curl_ipresolve = CURL_IPRESOLVE_WHATEVER;
  16 #else
  17 long int git_curl_ipresolve;
  18 #endif
  19 int active_requests;
  20 int http_is_verbose;
  21 size_t http_post_buffer = 16 * LARGE_PACKET_MAX;
  22
  23 #if LIBCURL_VERSION_NUM >= 0x070a06
  24 #define LIBCURL_CAN_HANDLE_AUTH_ANY
  25 #endif
  26
  27 static int min_curl_sessions = 1;
  28 static int curl_session_count;
  29 #ifdef USE_CURL_MULTI
  30 static int max_requests = -1;
  31 static CURLM *curlm;
  32 #endif
  33 #ifndef NO_CURL_EASY_DUPHANDLE
  34 static CURL *curl_default;
  35 #endif
  36
  37 #define PREV_BUF_SIZE 4096
  38
  39 char curl_errorstr[CURL_ERROR_SIZE];
  40
  41 static int curl_ssl_verify = -1;
  42 static int curl_ssl_try;
  43 static const char *ssl_cert;
  44 static const char *ssl_cipherlist;
  45 static const char *ssl_version;
  46 static struct {
  47         const char *name;
  48         long ssl_version;
  49 } sslversions[] = {
  50         { "sslv2", CURL_SSLVERSION_SSLv2 },
  51         { "sslv3", CURL_SSLVERSION_SSLv3 },
  52         { "tlsv1", CURL_SSLVERSION_TLSv1 },
  53 #if LIBCURL_VERSION_NUM >= 0x072200
  54         { "tlsv1.0", CURL_SSLVERSION_TLSv1_0 },
  55         { "tlsv1.1", CURL_SSLVERSION_TLSv1_1 },
  56         { "tlsv1.2", CURL_SSLVERSION_TLSv1_2 },
  57 #endif
  58 };
  59 #if LIBCURL_VERSION_NUM >= 0x070903
  60 static const char *ssl_key;
  61 #endif
  62 #if LIBCURL_VERSION_NUM >= 0x070908
  63 static const char *ssl_capath;
  64 #endif
  65 #if LIBCURL_VERSION_NUM >= 0x072c00
  66 static const char *ssl_pinnedkey;
  67 #endif
  68 static const char *ssl_cainfo;
  69 static long curl_low_speed_limit = -1;
  70 static long curl_low_speed_time = -1;
  71 static int curl_ftp_no_epsv;
  72 static const char *curl_http_proxy;
  73 static const char *curl_no_proxy;
  74 static const char *http_proxy_authmethod;
  75 static struct {
  76         const char *name;
  77         long curlauth_param;
  78 } proxy_authmethods[] = {
  79         { "basic", CURLAUTH_BASIC },
  80         { "digest", CURLAUTH_DIGEST },
  81         { "negotiate", CURLAUTH_GSSNEGOTIATE },
  82         { "ntlm", CURLAUTH_NTLM },
  83 #ifdef LIBCURL_CAN_HANDLE_AUTH_ANY
  84         { "anyauth", CURLAUTH_ANY },
  85 #endif
  86         /*
  87          * CURLAUTH_DIGEST_IE has no corresponding command-line option in
  88          * curl(1) and is not included in CURLAUTH_ANY, so we leave it out
  89          * here, too
  90          */
  91 };
  92 static struct credential proxy_auth = CREDENTIAL_INIT;
  93 static const char *curl_proxyuserpwd;
  94 static const char *curl_cookie_file;
  95 static int curl_save_cookies;
  96 struct credential http_auth = CREDENTIAL_INIT;
  97 static int http_proactive_auth;
  98 static const char *user_agent;
  99 static int curl_empty_auth;
 100
 101 #if LIBCURL_VERSION_NUM >= 0x071700
 102 /* Use CURLOPT_KEYPASSWD as is */
 103 #elif LIBCURL_VERSION_NUM >= 0x070903
 104 #define CURLOPT_KEYPASSWD CURLOPT_SSLKEYPASSWD
 105 #else
 106 #define CURLOPT_KEYPASSWD CURLOPT_SSLCERTPASSWD
 107 #endif
 108
 109 static struct credential cert_auth = CREDENTIAL_INIT;
 110 static int ssl_cert_password_required;
 111 #ifdef LIBCURL_CAN_HANDLE_AUTH_ANY
 112 static unsigned long http_auth_methods = CURLAUTH_ANY;
 113 #endif
 114
 115 static struct curl_slist *pragma_header;
 116 static struct curl_slist *no_pragma_header;
 117 static struct curl_slist *extra_http_headers;
 118
 119 static struct active_request_slot *active_queue_head;
 120
 121 static char *cached_accept_language;
 122
 123 size_t fread_buffer(char *ptr, size_t eltsize, size_t nmemb, void *buffer_)
 124 {
 125         size_t size = eltsize * nmemb;
 126         struct buffer *buffer = buffer_;
 127
 128         if (size > buffer->buf.len - buffer->posn)
 129                 size = buffer->buf.len - buffer->posn;
 130         memcpy(ptr, buffer->buf.buf + buffer->posn, size);
 131         buffer->posn += size;
 132
 133         return size;
 134 }
 135
 136 #ifndef NO_CURL_IOCTL
 137 curlioerr ioctl_buffer(CURL *handle, int cmd, void *clientp)
 138 {
 139         struct buffer *buffer = clientp;
 140
 141         switch (cmd) {
 142         case CURLIOCMD_NOP:
 143                 return CURLIOE_OK;
 144
 145         case CURLIOCMD_RESTARTREAD:
 146                 buffer->posn = 0;
 147                 return CURLIOE_OK;
 148
 149         default:
 150                 return CURLIOE_UNKNOWNCMD;
 151         }
 152 }
 153 #endif
 154
 155 size_t fwrite_buffer(char *ptr, size_t eltsize, size_t nmemb, void *buffer_)
 156 {
 157         size_t size = eltsize * nmemb;
 158         struct strbuf *buffer = buffer_;
 159
 160         strbuf_add(buffer, ptr, size);
 161         return size;
 162 }
 163
 164 size_t fwrite_null(char *ptr, size_t eltsize, size_t nmemb, void *strbuf)
 165 {
 166         return eltsize * nmemb;
 167 }
 168
 169 static void closedown_active_slot(struct active_request_slot *slot)
 170 {
 171         active_requests--;
 172         slot->in_use = 0;
 173 }
 174
 175 static void finish_active_slot(struct active_request_slot *slot)
 176 {
 177         closedown_active_slot(slot);
 178         curl_easy_getinfo(slot->curl, CURLINFO_HTTP_CODE, &slot->http_code);
 179
 180         if (slot->finished != NULL)
 181                 (*slot->finished) = 1;
 182
 183         /* Store slot results so they can be read after the slot is reused */
 184         if (slot->results != NULL) {
 185                 slot->results->curl_result = slot->curl_result;
 186                 slot->results->http_code = slot->http_code;
 187 #if LIBCURL_VERSION_NUM >= 0x070a08
 188                 curl_easy_getinfo(slot->curl, CURLINFO_HTTPAUTH_AVAIL,
 189                                   &slot->results->auth_avail);
 190 #else
 191                 slot->results->auth_avail = 0;
 192 #endif
 193
 194                 curl_easy_getinfo(slot->curl, CURLINFO_HTTP_CONNECTCODE,
 195                         &slot->results->http_connectcode);
 196         }
 197
 198         /* Run callback if appropriate */
 199         if (slot->callback_func != NULL)
 200                 slot->callback_func(slot->callback_data);
 201 }
 202
 203 #ifdef USE_CURL_MULTI
 204 static void process_curl_messages(void)
 205 {
 206         int num_messages;
 207         struct active_request_slot *slot;
 208         CURLMsg *curl_message = curl_multi_info_read(curlm, &num_messages);
 209
 210         while (curl_message != NULL) {
 211                 if (curl_message->msg == CURLMSG_DONE) {
 212                         int curl_result = curl_message->data.result;
 213                         slot = active_queue_head;
 214                         while (slot != NULL &&
 215                                slot->curl != curl_message->easy_handle)
 216                                 slot = slot->next;
 217                         if (slot != NULL) {
 218                                 curl_multi_remove_handle(curlm, slot->curl);
 219                                 slot->curl_result = curl_result;
 220                                 finish_active_slot(slot);
 221                         } else {
 222                                 fprintf(stderr, "Received DONE message for unknown request!\n");
 223                         }
 224                 } else {
 225                         fprintf(stderr, "Unknown CURL message received: %d\n",
 226                                 (int)curl_message->msg);
 227                 }
 228                 curl_message = curl_multi_info_read(curlm, &num_messages);
 229         }
 230 }
 231 #endif
 232
 233 static int http_options(const char *var, const char *value, void *cb)
 234 {
 235         if (!strcmp("http.sslverify", var)) {
 236                 curl_ssl_verify = git_config_bool(var, value);
 237                 return 0;
 238         }
 239         if (!strcmp("http.sslcipherlist", var))
 240                 return git_config_string(&ssl_cipherlist, var, value);
 241         if (!strcmp("http.sslversion", var))
 242                 return git_config_string(&ssl_version, var, value);
 243         if (!strcmp("http.sslcert", var))
 244                 return git_config_string(&ssl_cert, var, value);
 245 #if LIBCURL_VERSION_NUM >= 0x070903
 246         if (!strcmp("http.sslkey", var))
 247                 return git_config_string(&ssl_key, var, value);
 248 #endif
 249 #if LIBCURL_VERSION_NUM >= 0x070908
 250         if (!strcmp("http.sslcapath", var))
 251                 return git_config_pathname(&ssl_capath, var, value);
 252 #endif
 253         if (!strcmp("http.sslcainfo", var))
 254                 return git_config_pathname(&ssl_cainfo, var, value);
 255         if (!strcmp("http.sslcertpasswordprotected", var)) {
 256                 ssl_cert_password_required = git_config_bool(var, value);
 257                 return 0;
 258         }
 259         if (!strcmp("http.ssltry", var)) {
 260                 curl_ssl_try = git_config_bool(var, value);
 261                 return 0;
 262         }
 263         if (!strcmp("http.minsessions", var)) {
 264                 min_curl_sessions = git_config_int(var, value);
 265 #ifndef USE_CURL_MULTI
 266                 if (min_curl_sessions > 1)
 267                         min_curl_sessions = 1;
 268 #endif
 269                 return 0;
 270         }
 271 #ifdef USE_CURL_MULTI
 272         if (!strcmp("http.maxrequests", var)) {
 273                 max_requests = git_config_int(var, value);
 274                 return 0;
 275         }
 276 #endif
 277         if (!strcmp("http.lowspeedlimit", var)) {
 278                 curl_low_speed_limit = (long)git_config_int(var, value);
 279                 return 0;
 280         }
 281         if (!strcmp("http.lowspeedtime", var)) {
 282                 curl_low_speed_time = (long)git_config_int(var, value);
 283                 return 0;
 284         }
 285
 286         if (!strcmp("http.noepsv", var)) {
 287                 curl_ftp_no_epsv = git_config_bool(var, value);
 288                 return 0;
 289         }
 290         if (!strcmp("http.proxy", var))
 291                 return git_config_string(&curl_http_proxy, var, value);
 292
 293         if (!strcmp("http.proxyauthmethod", var))
 294                 return git_config_string(&http_proxy_authmethod, var, value);
 295
 296         if (!strcmp("http.cookiefile", var))
 297                 return git_config_pathname(&curl_cookie_file, var, value);
 298         if (!strcmp("http.savecookies", var)) {
 299                 curl_save_cookies = git_config_bool(var, value);
 300                 return 0;
 301         }
 302
 303         if (!strcmp("http.postbuffer", var)) {
 304                 http_post_buffer = git_config_int(var, value);
 305                 if (http_post_buffer < LARGE_PACKET_MAX)
 306                         http_post_buffer = LARGE_PACKET_MAX;
 307                 return 0;
 308         }
 309
 310         if (!strcmp("http.useragent", var))
 311                 return git_config_string(&user_agent, var, value);
 312
 313         if (!strcmp("http.emptyauth", var)) {
 314                 curl_empty_auth = git_config_bool(var, value);
 315                 return 0;
 316         }
 317
 318         if (!strcmp("http.pinnedpubkey", var)) {
 319 #if LIBCURL_VERSION_NUM >= 0x072c00
 320                 return git_config_pathname(&ssl_pinnedkey, var, value);
 321 #else
 322                 warning(_("Public key pinning not supported with cURL < 7.44.0"));
 323                 return 0;
 324 #endif
 325         }
 326
 327         if (!strcmp("http.extraheader", var)) {
 328                 if (!value) {
 329                         return config_error_nonbool(var);
 330                 } else if (!*value) {
 331                         curl_slist_free_all(extra_http_headers);
 332                         extra_http_headers = NULL;
 333                 } else {
 334                         extra_http_headers =
 335                                 curl_slist_append(extra_http_headers, value);
 336                 }
 337                 return 0;
 338         }
 339
 340         /* Fall back on the default ones */
 341         return git_default_config(var, value, cb);
 342 }
 343
 344 static void init_curl_http_auth(CURL *result)
 345 {
 346         if (!http_auth.username) {
 347                 if (curl_empty_auth)
 348                         curl_easy_setopt(result, CURLOPT_USERPWD, ":");
 349                 return;
 350         }
 351
 352         credential_fill(&http_auth);
 353
 354 #if LIBCURL_VERSION_NUM >= 0x071301
 355         curl_easy_setopt(result, CURLOPT_USERNAME, http_auth.username);
 356         curl_easy_setopt(result, CURLOPT_PASSWORD, http_auth.password);
 357 #else
 358         {
 359                 static struct strbuf up = STRBUF_INIT;
 360                 /*
 361                  * Note that we assume we only ever have a single set of
 362                  * credentials in a given program run, so we do not have
 363                  * to worry about updating this buffer, only setting its
 364                  * initial value.
 365                  */
 366                 if (!up.len)
 367                         strbuf_addf(&up, "%s:%s",
 368                                 http_auth.username, http_auth.password);
 369                 curl_easy_setopt(result, CURLOPT_USERPWD, up.buf);
 370         }
 371 #endif
 372 }
 373
 374 /* *var must be free-able */
 375 static void var_override(const char **var, char *value)
 376 {
 377         if (value) {
 378                 free((void *)*var);
 379                 *var = xstrdup(value);
 380         }
 381 }
 382
 383 static void set_proxyauth_name_password(CURL *result)
 384 {
 385 #if LIBCURL_VERSION_NUM >= 0x071301
 386                 curl_easy_setopt(result, CURLOPT_PROXYUSERNAME,
 387                         proxy_auth.username);
 388                 curl_easy_setopt(result, CURLOPT_PROXYPASSWORD,
 389                         proxy_auth.password);
 390 #else
 391                 struct strbuf s = STRBUF_INIT;
 392
 393                 strbuf_addstr_urlencode(&s, proxy_auth.username, 1);
 394                 strbuf_addch(&s, ':');
 395                 strbuf_addstr_urlencode(&s, proxy_auth.password, 1);
 396                 curl_proxyuserpwd = strbuf_detach(&s, NULL);
 397                 curl_easy_setopt(result, CURLOPT_PROXYUSERPWD, curl_proxyuserpwd);
 398 #endif
 399 }
 400
 401 static void init_curl_proxy_auth(CURL *result)
 402 {
 403         if (proxy_auth.username) {
 404                 if (!proxy_auth.password)
 405                         credential_fill(&proxy_auth);
 406                 set_proxyauth_name_password(result);
 407         }
 408
 409         var_override(&http_proxy_authmethod, getenv("GIT_HTTP_PROXY_AUTHMETHOD"));
 410
 411 #if LIBCURL_VERSION_NUM >= 0x070a07 /* CURLOPT_PROXYAUTH and CURLAUTH_ANY */
 412         if (http_proxy_authmethod) {
 413                 int i;
 414                 for (i = 0; i < ARRAY_SIZE(proxy_authmethods); i++) {
 415                         if (!strcmp(http_proxy_authmethod, proxy_authmethods[i].name)) {
 416                                 curl_easy_setopt(result, CURLOPT_PROXYAUTH,
 417                                                 proxy_authmethods[i].curlauth_param);
 418                                 break;
 419                         }
 420                 }
 421                 if (i == ARRAY_SIZE(proxy_authmethods)) {
 422                         warning("unsupported proxy authentication method %s: using anyauth",
 423                                         http_proxy_authmethod);
 424                         curl_easy_setopt(result, CURLOPT_PROXYAUTH, CURLAUTH_ANY);
 425                 }
 426         }
 427         else
 428                 curl_easy_setopt(result, CURLOPT_PROXYAUTH, CURLAUTH_ANY);
 429 #endif
 430 }
 431
 432 static int has_cert_password(void)
 433 {
 434         if (ssl_cert == NULL || ssl_cert_password_required != 1)
 435                 return 0;
 436         if (!cert_auth.password) {
 437                 cert_auth.protocol = xstrdup("cert");
 438                 cert_auth.username = xstrdup("");
 439                 cert_auth.path = xstrdup(ssl_cert);
 440                 credential_fill(&cert_auth);
 441         }
 442         return 1;
 443 }
 444
 445 #if LIBCURL_VERSION_NUM >= 0x071900
 446 static void set_curl_keepalive(CURL *c)
 447 {
 448         curl_easy_setopt(c, CURLOPT_TCP_KEEPALIVE, 1);
 449 }
 450
 451 #elif LIBCURL_VERSION_NUM >= 0x071000
 452 static int sockopt_callback(void *client, curl_socket_t fd, curlsocktype type)
 453 {
 454         int ka = 1;
 455         int rc;
 456         socklen_t len = (socklen_t)sizeof(ka);
 457
 458         if (type != CURLSOCKTYPE_IPCXN)
 459                 return 0;
 460
 461         rc = setsockopt(fd, SOL_SOCKET, SO_KEEPALIVE, (void *)&ka, len);
 462         if (rc < 0)
 463                 warning_errno("unable to set SO_KEEPALIVE on socket");
 464
 465         return 0; /* CURL_SOCKOPT_OK only exists since curl 7.21.5 */
 466 }
 467
 468 static void set_curl_keepalive(CURL *c)
 469 {
 470         curl_easy_setopt(c, CURLOPT_SOCKOPTFUNCTION, sockopt_callback);
 471 }
 472
 473 #else
 474 static void set_curl_keepalive(CURL *c)
 475 {
 476         /* not supported on older curl versions */
 477 }
 478 #endif
 479
 480 static CURL *get_curl_handle(void)
 481 {
 482         CURL *result = curl_easy_init();
 483         long allowed_protocols = 0;
 484
 485         if (!result)
 486                 die("curl_easy_init failed");
 487
 488         if (!curl_ssl_verify) {
 489                 curl_easy_setopt(result, CURLOPT_SSL_VERIFYPEER, 0);
 490                 curl_easy_setopt(result, CURLOPT_SSL_VERIFYHOST, 0);
 491         } else {
 492                 /* Verify authenticity of the peer's certificate */
 493                 curl_easy_setopt(result, CURLOPT_SSL_VERIFYPEER, 1);
 494                 /* The name in the cert must match whom we tried to connect */
 495                 curl_easy_setopt(result, CURLOPT_SSL_VERIFYHOST, 2);
 496         }
 497
 498 #if LIBCURL_VERSION_NUM >= 0x070907
 499         curl_easy_setopt(result, CURLOPT_NETRC, CURL_NETRC_OPTIONAL);
 500 #endif
 501 #ifdef LIBCURL_CAN_HANDLE_AUTH_ANY
 502         curl_easy_setopt(result, CURLOPT_HTTPAUTH, CURLAUTH_ANY);
 503 #endif
 504
 505         if (http_proactive_auth)
 506                 init_curl_http_auth(result);
 507
 508         if (getenv("GIT_SSL_VERSION"))
 509                 ssl_version = getenv("GIT_SSL_VERSION");
 510         if (ssl_version && *ssl_version) {
 511                 int i;
 512                 for (i = 0; i < ARRAY_SIZE(sslversions); i++) {
 513                         if (!strcmp(ssl_version, sslversions[i].name)) {
 514                                 curl_easy_setopt(result, CURLOPT_SSLVERSION,
 515                                                  sslversions[i].ssl_version);
 516                                 break;
 517                         }
 518                 }
 519                 if (i == ARRAY_SIZE(sslversions))
 520                         warning("unsupported ssl version %s: using default",
 521                                 ssl_version);
 522         }
 523
 524         if (getenv("GIT_SSL_CIPHER_LIST"))
 525                 ssl_cipherlist = getenv("GIT_SSL_CIPHER_LIST");
 526         if (ssl_cipherlist != NULL && *ssl_cipherlist)
 527                 curl_easy_setopt(result, CURLOPT_SSL_CIPHER_LIST,
 528                                 ssl_cipherlist);
 529
 530         if (ssl_cert != NULL)
 531                 curl_easy_setopt(result, CURLOPT_SSLCERT, ssl_cert);
 532         if (has_cert_password())
 533                 curl_easy_setopt(result, CURLOPT_KEYPASSWD, cert_auth.password);
 534 #if LIBCURL_VERSION_NUM >= 0x070903
 535         if (ssl_key != NULL)
 536                 curl_easy_setopt(result, CURLOPT_SSLKEY, ssl_key);
 537 #endif
 538 #if LIBCURL_VERSION_NUM >= 0x070908
 539         if (ssl_capath != NULL)
 540                 curl_easy_setopt(result, CURLOPT_CAPATH, ssl_capath);
 541 #endif
 542 #if LIBCURL_VERSION_NUM >= 0x072c00
 543         if (ssl_pinnedkey != NULL)
 544                 curl_easy_setopt(result, CURLOPT_PINNEDPUBLICKEY, ssl_pinnedkey);
 545 #endif
 546         if (ssl_cainfo != NULL)
 547                 curl_easy_setopt(result, CURLOPT_CAINFO, ssl_cainfo);
 548
 549         if (curl_low_speed_limit > 0 && curl_low_speed_time > 0) {
 550                 curl_easy_setopt(result, CURLOPT_LOW_SPEED_LIMIT,
 551                                  curl_low_speed_limit);
 552                 curl_easy_setopt(result, CURLOPT_LOW_SPEED_TIME,
 553                                  curl_low_speed_time);
 554         }
 555
 556         curl_easy_setopt(result, CURLOPT_FOLLOWLOCATION, 1);
 557         curl_easy_setopt(result, CURLOPT_MAXREDIRS, 20);
 558 #if LIBCURL_VERSION_NUM >= 0x071301
 559         curl_easy_setopt(result, CURLOPT_POSTREDIR, CURL_REDIR_POST_ALL);
 560 #elif LIBCURL_VERSION_NUM >= 0x071101
 561         curl_easy_setopt(result, CURLOPT_POST301, 1);
 562 #endif
 563 #if LIBCURL_VERSION_NUM >= 0x071304
 564         if (is_transport_allowed("http"))
 565                 allowed_protocols |= CURLPROTO_HTTP;
 566         if (is_transport_allowed("https"))
 567                 allowed_protocols |= CURLPROTO_HTTPS;
 568         if (is_transport_allowed("ftp"))
 569                 allowed_protocols |= CURLPROTO_FTP;
 570         if (is_transport_allowed("ftps"))
 571                 allowed_protocols |= CURLPROTO_FTPS;
 572         curl_easy_setopt(result, CURLOPT_REDIR_PROTOCOLS, allowed_protocols);
 573 #else
 574         if (transport_restrict_protocols())
 575                 warning("protocol restrictions not applied to curl redirects because\n"
 576                         "your curl version is too old (>= 7.19.4)");
 577 #endif
 578
 579         if (getenv("GIT_CURL_VERBOSE"))
 580                 curl_easy_setopt(result, CURLOPT_VERBOSE, 1);
 581
 582         curl_easy_setopt(result, CURLOPT_USERAGENT,
 583                 user_agent ? user_agent : git_user_agent());
 584
 585         if (curl_ftp_no_epsv)
 586                 curl_easy_setopt(result, CURLOPT_FTP_USE_EPSV, 0);
 587
 588 #ifdef CURLOPT_USE_SSL
 589         if (curl_ssl_try)
 590                 curl_easy_setopt(result, CURLOPT_USE_SSL, CURLUSESSL_TRY);
 591 #endif
 592
 593         /*
 594          * CURL also examines these variables as a fallback; but we need to query
 595          * them here in order to decide whether to prompt for missing password (cf.
 596          * init_curl_proxy_auth()).
 597          *
 598          * Unlike many other common environment variables, these are historically
 599          * lowercase only. It appears that CURL did not know this and implemented
 600          * only uppercase variants, which was later corrected to take both - with
 601          * the exception of http_proxy, which is lowercase only also in CURL. As
 602          * the lowercase versions are the historical quasi-standard, they take
 603          * precedence here, as in CURL.
 604          */
 605         if (!curl_http_proxy) {
 606                 if (!strcmp(http_auth.protocol, "https")) {
 607                         var_override(&curl_http_proxy, getenv("HTTPS_PROXY"));
 608                         var_override(&curl_http_proxy, getenv("https_proxy"));
 609                 } else {
 610                         var_override(&curl_http_proxy, getenv("http_proxy"));
 611                 }
 612                 if (!curl_http_proxy) {
 613                         var_override(&curl_http_proxy, getenv("ALL_PROXY"));
 614                         var_override(&curl_http_proxy, getenv("all_proxy"));
 615                 }
 616         }
 617
 618         if (curl_http_proxy) {
 619                 curl_easy_setopt(result, CURLOPT_PROXY, curl_http_proxy);
 620 #if LIBCURL_VERSION_NUM >= 0x071800
 621                 if (starts_with(curl_http_proxy, "socks5h"))
 622                         curl_easy_setopt(result,
 623                                 CURLOPT_PROXYTYPE, CURLPROXY_SOCKS5_HOSTNAME);
 624                 else if (starts_with(curl_http_proxy, "socks5"))
 625                         curl_easy_setopt(result,
 626                                 CURLOPT_PROXYTYPE, CURLPROXY_SOCKS5);
 627                 else if (starts_with(curl_http_proxy, "socks4a"))
 628                         curl_easy_setopt(result,
 629                                 CURLOPT_PROXYTYPE, CURLPROXY_SOCKS4A);
 630                 else if (starts_with(curl_http_proxy, "socks"))
 631                         curl_easy_setopt(result,
 632                                 CURLOPT_PROXYTYPE, CURLPROXY_SOCKS4);
 633 #endif
 634                 if (strstr(curl_http_proxy, "://"))
 635                         credential_from_url(&proxy_auth, curl_http_proxy);
 636                 else {
 637                         struct strbuf url = STRBUF_INIT;
 638                         strbuf_addf(&url, "http://%s", curl_http_proxy);
 639                         credential_from_url(&proxy_auth, url.buf);
 640                         strbuf_release(&url);
 641                 }
 642
 643                 curl_easy_setopt(result, CURLOPT_PROXY, proxy_auth.host);
 644 #if LIBCURL_VERSION_NUM >= 0x071304
 645                 var_override(&curl_no_proxy, getenv("NO_PROXY"));
 646                 var_override(&curl_no_proxy, getenv("no_proxy"));
 647                 curl_easy_setopt(result, CURLOPT_NOPROXY, curl_no_proxy);
 648 #endif
 649         }
 650         init_curl_proxy_auth(result);
 651
 652         set_curl_keepalive(result);
 653
 654         return result;
 655 }
 656
 657 static void set_from_env(const char **var, const char *envname)
 658 {
 659         const char *val = getenv(envname);
 660         if (val)
 661                 *var = val;
 662 }
 663
 664 void http_init(struct remote *remote, const char *url, int proactive_auth)
 665 {
 666         char *low_speed_limit;
 667         char *low_speed_time;
 668         char *normalized_url;
 669         struct urlmatch_config config = { STRING_LIST_INIT_DUP };
 670
 671         config.section = "http";
 672         config.key = NULL;
 673         config.collect_fn = http_options;
 674         config.cascade_fn = git_default_config;
 675         config.cb = NULL;
 676
 677         http_is_verbose = 0;
 678         normalized_url = url_normalize(url, &config.url);
 679
 680         git_config(urlmatch_config_entry, &config);
 681         free(normalized_url);
 682
 683         if (curl_global_init(CURL_GLOBAL_ALL) != CURLE_OK)
 684                 die("curl_global_init failed");
 685
 686         http_proactive_auth = proactive_auth;
 687
 688         if (remote && remote->http_proxy)
 689                 curl_http_proxy = xstrdup(remote->http_proxy);
 690
 691         if (remote)
 692                 var_override(&http_proxy_authmethod, remote->http_proxy_authmethod);
 693
 694         pragma_header = curl_slist_append(http_copy_default_headers(),
 695                 "Pragma: no-cache");
 696         no_pragma_header = curl_slist_append(http_copy_default_headers(),
 697                 "Pragma:");
 698
 699 #ifdef USE_CURL_MULTI
 700         {
 701                 char *http_max_requests = getenv("GIT_HTTP_MAX_REQUESTS");
 702                 if (http_max_requests != NULL)
 703                         max_requests = atoi(http_max_requests);
 704         }
 705
 706         curlm = curl_multi_init();
 707         if (!curlm)
 708                 die("curl_multi_init failed");
 709 #endif
 710
 711         if (getenv("GIT_SSL_NO_VERIFY"))
 712                 curl_ssl_verify = 0;
 713
 714         set_from_env(&ssl_cert, "GIT_SSL_CERT");
 715 #if LIBCURL_VERSION_NUM >= 0x070903
 716         set_from_env(&ssl_key, "GIT_SSL_KEY");
 717 #endif
 718 #if LIBCURL_VERSION_NUM >= 0x070908
 719         set_from_env(&ssl_capath, "GIT_SSL_CAPATH");
 720 #endif
 721         set_from_env(&ssl_cainfo, "GIT_SSL_CAINFO");
 722
 723         set_from_env(&user_agent, "GIT_HTTP_USER_AGENT");
 724
 725         low_speed_limit = getenv("GIT_HTTP_LOW_SPEED_LIMIT");
 726         if (low_speed_limit != NULL)
 727                 curl_low_speed_limit = strtol(low_speed_limit, NULL, 10);
 728         low_speed_time = getenv("GIT_HTTP_LOW_SPEED_TIME");
 729         if (low_speed_time != NULL)
 730                 curl_low_speed_time = strtol(low_speed_time, NULL, 10);
 731
 732         if (curl_ssl_verify == -1)
 733                 curl_ssl_verify = 1;
 734
 735         curl_session_count = 0;
 736 #ifdef USE_CURL_MULTI
 737         if (max_requests < 1)
 738                 max_requests = DEFAULT_MAX_REQUESTS;
 739 #endif
 740
 741         if (getenv("GIT_CURL_FTP_NO_EPSV"))
 742                 curl_ftp_no_epsv = 1;
 743
 744         if (url) {
 745                 credential_from_url(&http_auth, url);
 746                 if (!ssl_cert_password_required &&
 747                     getenv("GIT_SSL_CERT_PASSWORD_PROTECTED") &&
 748                     starts_with(url, "https://"))
 749                         ssl_cert_password_required = 1;
 750         }
 751
 752 #ifndef NO_CURL_EASY_DUPHANDLE
 753         curl_default = get_curl_handle();
 754 #endif
 755 }
 756
 757 void http_cleanup(void)
 758 {
 759         struct active_request_slot *slot = active_queue_head;
 760
 761         while (slot != NULL) {
 762                 struct active_request_slot *next = slot->next;
 763                 if (slot->curl != NULL) {
 764 #ifdef USE_CURL_MULTI
 765                         curl_multi_remove_handle(curlm, slot->curl);
 766 #endif
 767                         curl_easy_cleanup(slot->curl);
 768                 }
 769                 free(slot);
 770                 slot = next;
 771         }
 772         active_queue_head = NULL;
 773
 774 #ifndef NO_CURL_EASY_DUPHANDLE
 775         curl_easy_cleanup(curl_default);
 776 #endif
 777
 778 #ifdef USE_CURL_MULTI
 779         curl_multi_cleanup(curlm);
 780 #endif
 781         curl_global_cleanup();
 782
 783         curl_slist_free_all(extra_http_headers);
 784         extra_http_headers = NULL;
 785
 786         curl_slist_free_all(pragma_header);
 787         pragma_header = NULL;
 788
 789         curl_slist_free_all(no_pragma_header);
 790         no_pragma_header = NULL;
 791
 792         if (curl_http_proxy) {
 793                 free((void *)curl_http_proxy);
 794                 curl_http_proxy = NULL;
 795         }
 796
 797         if (proxy_auth.password) {
 798                 memset(proxy_auth.password, 0, strlen(proxy_auth.password));
 799                 free(proxy_auth.password);
 800                 proxy_auth.password = NULL;
 801         }
 802
 803         free((void *)curl_proxyuserpwd);
 804         curl_proxyuserpwd = NULL;
 805
 806         free((void *)http_proxy_authmethod);
 807         http_proxy_authmethod = NULL;
 808
 809         if (cert_auth.password != NULL) {
 810                 memset(cert_auth.password, 0, strlen(cert_auth.password));
 811                 free(cert_auth.password);
 812                 cert_auth.password = NULL;
 813         }
 814         ssl_cert_password_required = 0;
 815
 816         free(cached_accept_language);
 817         cached_accept_language = NULL;
 818 }
 819
 820 struct active_request_slot *get_active_slot(void)
 821 {
 822         struct active_request_slot *slot = active_queue_head;
 823         struct active_request_slot *newslot;
 824
 825 #ifdef USE_CURL_MULTI
 826         int num_transfers;
 827
 828         /* Wait for a slot to open up if the queue is full */
 829         while (active_requests >= max_requests) {
 830                 curl_multi_perform(curlm, &num_transfers);
 831                 if (num_transfers < active_requests)
 832                         process_curl_messages();
 833         }
 834 #endif
 835
 836         while (slot != NULL && slot->in_use)
 837                 slot = slot->next;
 838
 839         if (slot == NULL) {
 840                 newslot = xmalloc(sizeof(*newslot));
 841                 newslot->curl = NULL;
 842                 newslot->in_use = 0;
 843                 newslot->next = NULL;
 844
 845                 slot = active_queue_head;
 846                 if (slot == NULL) {
 847                         active_queue_head = newslot;
 848                 } else {
 849                         while (slot->next != NULL)
 850                                 slot = slot->next;
 851                         slot->next = newslot;
 852                 }
 853                 slot = newslot;
 854         }
 855
 856         if (slot->curl == NULL) {
 857 #ifdef NO_CURL_EASY_DUPHANDLE
 858                 slot->curl = get_curl_handle();
 859 #else
 860                 slot->curl = curl_easy_duphandle(curl_default);
 861 #endif
 862                 curl_session_count++;
 863         }
 864
 865         active_requests++;
 866         slot->in_use = 1;
 867         slot->results = NULL;
 868         slot->finished = NULL;
 869         slot->callback_data = NULL;
 870         slot->callback_func = NULL;
 871         curl_easy_setopt(slot->curl, CURLOPT_COOKIEFILE, curl_cookie_file);
 872         if (curl_save_cookies)
 873                 curl_easy_setopt(slot->curl, CURLOPT_COOKIEJAR, curl_cookie_file);
 874         curl_easy_setopt(slot->curl, CURLOPT_HTTPHEADER, pragma_header);
 875         curl_easy_setopt(slot->curl, CURLOPT_ERRORBUFFER, curl_errorstr);
 876         curl_easy_setopt(slot->curl, CURLOPT_CUSTOMREQUEST, NULL);
 877         curl_easy_setopt(slot->curl, CURLOPT_READFUNCTION, NULL);
 878         curl_easy_setopt(slot->curl, CURLOPT_WRITEFUNCTION, NULL);
 879         curl_easy_setopt(slot->curl, CURLOPT_POSTFIELDS, NULL);
 880         curl_easy_setopt(slot->curl, CURLOPT_UPLOAD, 0);
 881         curl_easy_setopt(slot->curl, CURLOPT_HTTPGET, 1);
 882         curl_easy_setopt(slot->curl, CURLOPT_FAILONERROR, 1);
 883         curl_easy_setopt(slot->curl, CURLOPT_RANGE, NULL);
 884
 885 #if LIBCURL_VERSION_NUM >= 0x070a08
 886         curl_easy_setopt(slot->curl, CURLOPT_IPRESOLVE, git_curl_ipresolve);
 887 #endif
 888 #ifdef LIBCURL_CAN_HANDLE_AUTH_ANY
 889         curl_easy_setopt(slot->curl, CURLOPT_HTTPAUTH, http_auth_methods);
 890 #endif
 891         if (http_auth.password || curl_empty_auth)
 892                 init_curl_http_auth(slot->curl);
 893
 894         return slot;
 895 }
 896
 897 int start_active_slot(struct active_request_slot *slot)
 898 {
 899 #ifdef USE_CURL_MULTI
 900         CURLMcode curlm_result = curl_multi_add_handle(curlm, slot->curl);
 901         int num_transfers;
 902
 903         if (curlm_result != CURLM_OK &&
 904             curlm_result != CURLM_CALL_MULTI_PERFORM) {
 905                 active_requests--;
 906                 slot->in_use = 0;
 907                 return 0;
 908         }
 909
 910         /*
 911          * We know there must be something to do, since we just added
 912          * something.
 913          */
 914         curl_multi_perform(curlm, &num_transfers);
 915 #endif
 916         return 1;
 917 }
 918
 919 #ifdef USE_CURL_MULTI
 920 struct fill_chain {
 921         void *data;
 922         int (*fill)(void *);
 923         struct fill_chain *next;
 924 };
 925
 926 static struct fill_chain *fill_cfg;
 927
 928 void add_fill_function(void *data, int (*fill)(void *))
 929 {
 930         struct fill_chain *new = xmalloc(sizeof(*new));
 931         struct fill_chain **linkp = &fill_cfg;
 932         new->data = data;
 933         new->fill = fill;
 934         new->next = NULL;
 935         while (*linkp)
 936                 linkp = &(*linkp)->next;
 937         *linkp = new;
 938 }
 939
 940 void fill_active_slots(void)
 941 {
 942         struct active_request_slot *slot = active_queue_head;
 943
 944         while (active_requests < max_requests) {
 945                 struct fill_chain *fill;
 946                 for (fill = fill_cfg; fill; fill = fill->next)
 947                         if (fill->fill(fill->data))
 948                                 break;
 949
 950                 if (!fill)
 951                         break;
 952         }
 953
 954         while (slot != NULL) {
 955                 if (!slot->in_use && slot->curl != NULL
 956                         && curl_session_count > min_curl_sessions) {
 957                         curl_easy_cleanup(slot->curl);
 958                         slot->curl = NULL;
 959                         curl_session_count--;
 960                 }
 961                 slot = slot->next;
 962         }
 963 }
 964
 965 void step_active_slots(void)
 966 {
 967         int num_transfers;
 968         CURLMcode curlm_result;
 969
 970         do {
 971                 curlm_result = curl_multi_perform(curlm, &num_transfers);
 972         } while (curlm_result == CURLM_CALL_MULTI_PERFORM);
 973         if (num_transfers < active_requests) {
 974                 process_curl_messages();
 975                 fill_active_slots();
 976         }
 977 }
 978 #endif
 979
 980 void run_active_slot(struct active_request_slot *slot)
 981 {
 982 #ifdef USE_CURL_MULTI
 983         fd_set readfds;
 984         fd_set writefds;
 985         fd_set excfds;
 986         int max_fd;
 987         struct timeval select_timeout;
 988         int finished = 0;
 989
 990         slot->finished = &finished;
 991         while (!finished) {
 992                 step_active_slots();
 993
 994                 if (slot->in_use) {
 995 #if LIBCURL_VERSION_NUM >= 0x070f04
 996                         long curl_timeout;
 997                         curl_multi_timeout(curlm, &curl_timeout);
 998                         if (curl_timeout == 0) {
 999                                 continue;
1000                         } else if (curl_timeout == -1) {
1001                                 select_timeout.tv_sec  = 0;
1002                                 select_timeout.tv_usec = 50000;
1003                         } else {
1004                                 select_timeout.tv_sec  =  curl_timeout / 1000;
1005                                 select_timeout.tv_usec = (curl_timeout % 1000) * 1000;
1006                         }
1007 #else
1008                         select_timeout.tv_sec  = 0;
1009                         select_timeout.tv_usec = 50000;
1010 #endif
1011
1012                         max_fd = -1;
1013                         FD_ZERO(&readfds);
1014                         FD_ZERO(&writefds);
1015                         FD_ZERO(&excfds);
1016                         curl_multi_fdset(curlm, &readfds, &writefds, &excfds, &max_fd);
1017
1018                         /*
1019                          * It can happen that curl_multi_timeout returns a pathologically
1020                          * long timeout when curl_multi_fdset returns no file descriptors
1021                          * to read.  See commit message for more details.
1022                          */
1023                         if (max_fd < 0 &&
1024                             (select_timeout.tv_sec > 0 ||
1025                              select_timeout.tv_usec > 50000)) {
1026                                 select_timeout.tv_sec  = 0;
1027                                 select_timeout.tv_usec = 50000;
1028                         }
1029
1030                         select(max_fd+1, &readfds, &writefds, &excfds, &select_timeout);
1031                 }
1032         }
1033 #else
1034         while (slot->in_use) {
1035                 slot->curl_result = curl_easy_perform(slot->curl);
1036                 finish_active_slot(slot);
1037         }
1038 #endif
1039 }
1040
1041 static void release_active_slot(struct active_request_slot *slot)
1042 {
1043         closedown_active_slot(slot);
1044         if (slot->curl && curl_session_count > min_curl_sessions) {
1045 #ifdef USE_CURL_MULTI
1046                 curl_multi_remove_handle(curlm, slot->curl);
1047 #endif
1048                 curl_easy_cleanup(slot->curl);
1049                 slot->curl = NULL;
1050                 curl_session_count--;
1051         }
1052 #ifdef USE_CURL_MULTI
1053         fill_active_slots();
1054 #endif
1055 }
1056
1057 void finish_all_active_slots(void)
1058 {
1059         struct active_request_slot *slot = active_queue_head;
1060
1061         while (slot != NULL)
1062                 if (slot->in_use) {
1063                         run_active_slot(slot);
1064                         slot = active_queue_head;
1065                 } else {
1066                         slot = slot->next;
1067                 }
1068 }
1069
1070 /* Helpers for modifying and creating URLs */
1071 static inline int needs_quote(int ch)
1072 {
1073         if (((ch >= 'A') && (ch <= 'Z'))
1074                         || ((ch >= 'a') && (ch <= 'z'))
1075                         || ((ch >= '0') && (ch <= '9'))
1076                         || (ch == '/')
1077                         || (ch == '-')
1078                         || (ch == '.'))
1079                 return 0;
1080         return 1;
1081 }
1082
1083 static char *quote_ref_url(const char *base, const char *ref)
1084 {
1085         struct strbuf buf = STRBUF_INIT;
1086         const char *cp;
1087         int ch;
1088
1089         end_url_with_slash(&buf, base);
1090
1091         for (cp = ref; (ch = *cp) != 0; cp++)
1092                 if (needs_quote(ch))
1093                         strbuf_addf(&buf, "%%%02x", ch);
1094                 else
1095                         strbuf_addch(&buf, *cp);
1096
1097         return strbuf_detach(&buf, NULL);
1098 }
1099
1100 void append_remote_object_url(struct strbuf *buf, const char *url,
1101                               const char *hex,
1102                               int only_two_digit_prefix)
1103 {
1104         end_url_with_slash(buf, url);
1105
1106         strbuf_addf(buf, "objects/%.*s/", 2, hex);
1107         if (!only_two_digit_prefix)
1108                 strbuf_addstr(buf, hex + 2);
1109 }
1110
1111 char *get_remote_object_url(const char *url, const char *hex,
1112                             int only_two_digit_prefix)
1113 {
1114         struct strbuf buf = STRBUF_INIT;
1115         append_remote_object_url(&buf, url, hex, only_two_digit_prefix);
1116         return strbuf_detach(&buf, NULL);
1117 }
1118
1119 static int handle_curl_result(struct slot_results *results)
1120 {
1121         /*
1122          * If we see a failing http code with CURLE_OK, we have turned off
1123          * FAILONERROR (to keep the server's custom error response), and should
1124          * translate the code into failure here.
1125          */
1126         if (results->curl_result == CURLE_OK &&
1127             results->http_code >= 400) {
1128                 results->curl_result = CURLE_HTTP_RETURNED_ERROR;
1129                 /*
1130                  * Normally curl will already have put the "reason phrase"
1131                  * from the server into curl_errorstr; unfortunately without
1132                  * FAILONERROR it is lost, so we can give only the numeric
1133                  * status code.
1134                  */
1135                 snprintf(curl_errorstr, sizeof(curl_errorstr),
1136                          "The requested URL returned error: %ld",
1137                          results->http_code);
1138         }
1139
1140         if (results->curl_result == CURLE_OK) {
1141                 credential_approve(&http_auth);
1142                 if (proxy_auth.password)
1143                         credential_approve(&proxy_auth);
1144                 return HTTP_OK;
1145         } else if (missing_target(results))
1146                 return HTTP_MISSING_TARGET;
1147         else if (results->http_code == 401) {
1148                 if (http_auth.username && http_auth.password) {
1149                         credential_reject(&http_auth);
1150                         return HTTP_NOAUTH;
1151                 } else {
1152 #ifdef LIBCURL_CAN_HANDLE_AUTH_ANY
1153                         http_auth_methods &= ~CURLAUTH_GSSNEGOTIATE;
1154 #endif
1155                         return HTTP_REAUTH;
1156                 }
1157         } else {
1158                 if (results->http_connectcode == 407)
1159                         credential_reject(&proxy_auth);
1160 #if LIBCURL_VERSION_NUM >= 0x070c00
1161                 if (!curl_errorstr[0])
1162                         strlcpy(curl_errorstr,
1163                                 curl_easy_strerror(results->curl_result),
1164                                 sizeof(curl_errorstr));
1165 #endif
1166                 return HTTP_ERROR;
1167         }
1168 }
1169
1170 int run_one_slot(struct active_request_slot *slot,
1171                  struct slot_results *results)
1172 {
1173         slot->results = results;
1174         if (!start_active_slot(slot)) {
1175                 snprintf(curl_errorstr, sizeof(curl_errorstr),
1176                          "failed to start HTTP request");
1177                 return HTTP_START_FAILED;
1178         }
1179
1180         run_active_slot(slot);
1181         return handle_curl_result(results);
1182 }
1183
1184 struct curl_slist *http_copy_default_headers(void)
1185 {
1186         struct curl_slist *headers = NULL, *h;
1187
1188         for (h = extra_http_headers; h; h = h->next)
1189                 headers = curl_slist_append(headers, h->data);
1190
1191         return headers;
1192 }
1193
1194 static CURLcode curlinfo_strbuf(CURL *curl, CURLINFO info, struct strbuf *buf)
1195 {
1196         char *ptr;
1197         CURLcode ret;
1198
1199         strbuf_reset(buf);
1200         ret = curl_easy_getinfo(curl, info, &ptr);
1201         if (!ret && ptr)
1202                 strbuf_addstr(buf, ptr);
1203         return ret;
1204 }
1205
1206 /*
1207  * Check for and extract a content-type parameter. "raw"
1208  * should be positioned at the start of the potential
1209  * parameter, with any whitespace already removed.
1210  *
1211  * "name" is the name of the parameter. The value is appended
1212  * to "out".
1213  */
1214 static int extract_param(const char *raw, const char *name,
1215                          struct strbuf *out)
1216 {
1217         size_t len = strlen(name);
1218
1219         if (strncasecmp(raw, name, len))
1220                 return -1;
1221         raw += len;
1222
1223         if (*raw != '=')
1224                 return -1;
1225         raw++;
1226
1227         while (*raw && !isspace(*raw) && *raw != ';')
1228                 strbuf_addch(out, *raw++);
1229         return 0;
1230 }
1231
1232 /*
1233  * Extract a normalized version of the content type, with any
1234  * spaces suppressed, all letters lowercased, and no trailing ";"
1235  * or parameters.
1236  *
1237  * Note that we will silently remove even invalid whitespace. For
1238  * example, "text / plain" is specifically forbidden by RFC 2616,
1239  * but "text/plain" is the only reasonable output, and this keeps
1240  * our code simple.
1241  *
1242  * If the "charset" argument is not NULL, store the value of any
1243  * charset parameter there.
1244  *
1245  * Example:
1246  *   "TEXT/PLAIN; charset=utf-8" -> "text/plain", "utf-8"
1247  *   "text / plain" -> "text/plain"
1248  */
1249 static void extract_content_type(struct strbuf *raw, struct strbuf *type,
1250                                  struct strbuf *charset)
1251 {
1252         const char *p;
1253
1254         strbuf_reset(type);
1255         strbuf_grow(type, raw->len);
1256         for (p = raw->buf; *p; p++) {
1257                 if (isspace(*p))
1258                         continue;
1259                 if (*p == ';') {
1260                         p++;
1261                         break;
1262                 }
1263                 strbuf_addch(type, tolower(*p));
1264         }
1265
1266         if (!charset)
1267                 return;
1268
1269         strbuf_reset(charset);
1270         while (*p) {
1271                 while (isspace(*p) || *p == ';')
1272                         p++;
1273                 if (!extract_param(p, "charset", charset))
1274                         return;
1275                 while (*p && !isspace(*p))
1276                         p++;
1277         }
1278
1279         if (!charset->len && starts_with(type->buf, "text/"))
1280                 strbuf_addstr(charset, "ISO-8859-1");
1281 }
1282
1283 static void write_accept_language(struct strbuf *buf)
1284 {
1285         /*
1286          * MAX_DECIMAL_PLACES must not be larger than 3. If it is larger than
1287          * that, q-value will be smaller than 0.001, the minimum q-value the
1288          * HTTP specification allows. See
1289          * http://tools.ietf.org/html/rfc7231#section-5.3.1 for q-value.
1290          */
1291         const int MAX_DECIMAL_PLACES = 3;
1292         const int MAX_LANGUAGE_TAGS = 1000;
1293         const int MAX_ACCEPT_LANGUAGE_HEADER_SIZE = 4000;
1294         char **language_tags = NULL;
1295         int num_langs = 0;
1296         const char *s = get_preferred_languages();
1297         int i;
1298         struct strbuf tag = STRBUF_INIT;
1299
1300         /* Don't add Accept-Language header if no language is preferred. */
1301         if (!s)
1302                 return;
1303
1304         /*
1305          * Split the colon-separated string of preferred languages into
1306          * language_tags array.
1307          */
1308         do {
1309                 /* collect language tag */
1310                 for (; *s && (isalnum(*s) || *s == '_'); s++)
1311                         strbuf_addch(&tag, *s == '_' ? '-' : *s);
1312
1313                 /* skip .codeset, @modifier and any other unnecessary parts */
1314                 while (*s && *s != ':')
1315                         s++;
1316
1317                 if (tag.len) {
1318                         num_langs++;
1319                         REALLOC_ARRAY(language_tags, num_langs);
1320                         language_tags[num_langs - 1] = strbuf_detach(&tag, NULL);
1321                         if (num_langs >= MAX_LANGUAGE_TAGS - 1) /* -1 for '*' */
1322                                 break;
1323                 }
1324         } while (*s++);
1325
1326         /* write Accept-Language header into buf */
1327         if (num_langs) {
1328                 int last_buf_len = 0;
1329                 int max_q;
1330                 int decimal_places;
1331                 char q_format[32];
1332
1333                 /* add '*' */
1334                 REALLOC_ARRAY(language_tags, num_langs + 1);
1335                 language_tags[num_langs++] = "*"; /* it's OK; this won't be freed */
1336
1337                 /* compute decimal_places */
1338                 for (max_q = 1, decimal_places = 0;
1339                      max_q < num_langs && decimal_places <= MAX_DECIMAL_PLACES;
1340                      decimal_places++, max_q *= 10)
1341                         ;
1342
1343                 xsnprintf(q_format, sizeof(q_format), ";q=0.%%0%dd", decimal_places);
1344
1345                 strbuf_addstr(buf, "Accept-Language: ");
1346
1347                 for (i = 0; i < num_langs; i++) {
1348                         if (i > 0)
1349                                 strbuf_addstr(buf, ", ");
1350
1351                         strbuf_addstr(buf, language_tags[i]);
1352
1353                         if (i > 0)
1354                                 strbuf_addf(buf, q_format, max_q - i);
1355
1356                         if (buf->len > MAX_ACCEPT_LANGUAGE_HEADER_SIZE) {
1357                                 strbuf_remove(buf, last_buf_len, buf->len - last_buf_len);
1358                                 break;
1359                         }
1360
1361                         last_buf_len = buf->len;
1362                 }
1363         }
1364
1365         /* free language tags -- last one is a static '*' */
1366         for (i = 0; i < num_langs - 1; i++)
1367                 free(language_tags[i]);
1368         free(language_tags);
1369 }
1370
1371 /*
1372  * Get an Accept-Language header which indicates user's preferred languages.
1373  *
1374  * Examples:
1375  *   LANGUAGE= -> ""
1376  *   LANGUAGE=ko:en -> "Accept-Language: ko, en; q=0.9, *; q=0.1"
1377  *   LANGUAGE=ko_KR.UTF-8:sr@latin -> "Accept-Language: ko-KR, sr; q=0.9, *; q=0.1"
1378  *   LANGUAGE=ko LANG=en_US.UTF-8 -> "Accept-Language: ko, *; q=0.1"
1379  *   LANGUAGE= LANG=en_US.UTF-8 -> "Accept-Language: en-US, *; q=0.1"
1380  *   LANGUAGE= LANG=C -> ""
1381  */
1382 static const char *get_accept_language(void)
1383 {
1384         if (!cached_accept_language) {
1385                 struct strbuf buf = STRBUF_INIT;
1386                 write_accept_language(&buf);
1387                 if (buf.len > 0)
1388                         cached_accept_language = strbuf_detach(&buf, NULL);
1389         }
1390
1391         return cached_accept_language;
1392 }
1393
1394 static void http_opt_request_remainder(CURL *curl, off_t pos)
1395 {
1396         char buf[128];
1397         xsnprintf(buf, sizeof(buf), "%"PRIuMAX"-", (uintmax_t)pos);
1398         curl_easy_setopt(curl, CURLOPT_RANGE, buf);
1399 }
1400
1401 /* http_request() targets */
1402 #define HTTP_REQUEST_STRBUF     0
1403 #define HTTP_REQUEST_FILE       1
1404
1405 static int http_request(const char *url,
1406                         void *result, int target,
1407                         const struct http_get_options *options)
1408 {
1409         struct active_request_slot *slot;
1410         struct slot_results results;
1411         struct curl_slist *headers = http_copy_default_headers();
1412         struct strbuf buf = STRBUF_INIT;
1413         const char *accept_language;
1414         int ret;
1415
1416         slot = get_active_slot();
1417         curl_easy_setopt(slot->curl, CURLOPT_HTTPGET, 1);
1418
1419         if (result == NULL) {
1420                 curl_easy_setopt(slot->curl, CURLOPT_NOBODY, 1);
1421         } else {
1422                 curl_easy_setopt(slot->curl, CURLOPT_NOBODY, 0);
1423                 curl_easy_setopt(slot->curl, CURLOPT_FILE, result);
1424
1425                 if (target == HTTP_REQUEST_FILE) {
1426                         off_t posn = ftello(result);
1427                         curl_easy_setopt(slot->curl, CURLOPT_WRITEFUNCTION,
1428                                          fwrite);
1429                         if (posn > 0)
1430                                 http_opt_request_remainder(slot->curl, posn);
1431                 } else
1432                         curl_easy_setopt(slot->curl, CURLOPT_WRITEFUNCTION,
1433                                          fwrite_buffer);
1434         }
1435
1436         accept_language = get_accept_language();
1437
1438         if (accept_language)
1439                 headers = curl_slist_append(headers, accept_language);
1440
1441         strbuf_addstr(&buf, "Pragma:");
1442         if (options && options->no_cache)
1443                 strbuf_addstr(&buf, " no-cache");
1444         if (options && options->keep_error)
1445                 curl_easy_setopt(slot->curl, CURLOPT_FAILONERROR, 0);
1446
1447         headers = curl_slist_append(headers, buf.buf);
1448
1449         curl_easy_setopt(slot->curl, CURLOPT_URL, url);
1450         curl_easy_setopt(slot->curl, CURLOPT_HTTPHEADER, headers);
1451         curl_easy_setopt(slot->curl, CURLOPT_ENCODING, "gzip");
1452
1453         ret = run_one_slot(slot, &results);
1454
1455         if (options && options->content_type) {
1456                 struct strbuf raw = STRBUF_INIT;
1457                 curlinfo_strbuf(slot->curl, CURLINFO_CONTENT_TYPE, &raw);
1458                 extract_content_type(&raw, options->content_type,
1459                                      options->charset);
1460                 strbuf_release(&raw);
1461         }
1462
1463         if (options && options->effective_url)
1464                 curlinfo_strbuf(slot->curl, CURLINFO_EFFECTIVE_URL,
1465                                 options->effective_url);
1466
1467         curl_slist_free_all(headers);
1468         strbuf_release(&buf);
1469
1470         return ret;
1471 }
1472
1473 /*
1474  * Update the "base" url to a more appropriate value, as deduced by
1475  * redirects seen when requesting a URL starting with "url".
1476  *
1477  * The "asked" parameter is a URL that we asked curl to access, and must begin
1478  * with "base".
1479  *
1480  * The "got" parameter is the URL that curl reported to us as where we ended
1481  * up.
1482  *
1483  * Returns 1 if we updated the base url, 0 otherwise.
1484  *
1485  * Our basic strategy is to compare "base" and "asked" to find the bits
1486  * specific to our request. We then strip those bits off of "got" to yield the
1487  * new base. So for example, if our base is "http://example.com/foo.git",
1488  * and we ask for "http://example.com/foo.git/info/refs", we might end up
1489  * with "https://other.example.com/foo.git/info/refs". We would want the
1490  * new URL to become "https://other.example.com/foo.git".
1491  *
1492  * Note that this assumes a sane redirect scheme. It's entirely possible
1493  * in the example above to end up at a URL that does not even end in
1494  * "info/refs".  In such a case we simply punt, as there is not much we can
1495  * do (and such a scheme is unlikely to represent a real git repository,
1496  * which means we are likely about to abort anyway).
1497  */
1498 static int update_url_from_redirect(struct strbuf *base,
1499                                     const char *asked,
1500                                     const struct strbuf *got)
1501 {
1502         const char *tail;
1503         size_t tail_len;
1504
1505         if (!strcmp(asked, got->buf))
1506                 return 0;
1507
1508         if (!skip_prefix(asked, base->buf, &tail))
1509                 die("BUG: update_url_from_redirect: %s is not a superset of %s",
1510                     asked, base->buf);
1511
1512         tail_len = strlen(tail);
1513
1514         if (got->len < tail_len ||
1515             strcmp(tail, got->buf + got->len - tail_len))
1516                 return 0; /* insane redirect scheme */
1517
1518         strbuf_reset(base);
1519         strbuf_add(base, got->buf, got->len - tail_len);
1520         return 1;
1521 }
1522
1523 static int http_request_reauth(const char *url,
1524                                void *result, int target,
1525                                struct http_get_options *options)
1526 {
1527         int ret = http_request(url, result, target, options);
1528
1529         if (options && options->effective_url && options->base_url) {
1530                 if (update_url_from_redirect(options->base_url,
1531                                              url, options->effective_url)) {
1532                         credential_from_url(&http_auth, options->base_url->buf);
1533                         url = options->effective_url->buf;
1534                 }
1535         }
1536
1537         if (ret != HTTP_REAUTH)
1538                 return ret;
1539
1540         /*
1541          * If we are using KEEP_ERROR, the previous request may have
1542          * put cruft into our output stream; we should clear it out before
1543          * making our next request. We only know how to do this for
1544          * the strbuf case, but that is enough to satisfy current callers.
1545          */
1546         if (options && options->keep_error) {
1547                 switch (target) {
1548                 case HTTP_REQUEST_STRBUF:
1549                         strbuf_reset(result);
1550                         break;
1551                 default:
1552                         die("BUG: HTTP_KEEP_ERROR is only supported with strbufs");
1553                 }
1554         }
1555
1556         credential_fill(&http_auth);
1557
1558         return http_request(url, result, target, options);
1559 }
1560
1561 int http_get_strbuf(const char *url,
1562                     struct strbuf *result,
1563                     struct http_get_options *options)
1564 {
1565         return http_request_reauth(url, result, HTTP_REQUEST_STRBUF, options);
1566 }
1567
1568 /*
1569  * Downloads a URL and stores the result in the given file.
1570  *
1571  * If a previous interrupted download is detected (i.e. a previous temporary
1572  * file is still around) the download is resumed.
1573  */
1574 static int http_get_file(const char *url, const char *filename,
1575                          struct http_get_options *options)
1576 {
1577         int ret;
1578         struct strbuf tmpfile = STRBUF_INIT;
1579         FILE *result;
1580
1581         strbuf_addf(&tmpfile, "%s.temp", filename);
1582         result = fopen(tmpfile.buf, "a");
1583         if (!result) {
1584                 error("Unable to open local file %s", tmpfile.buf);
1585                 ret = HTTP_ERROR;
1586                 goto cleanup;
1587         }
1588
1589         ret = http_request_reauth(url, result, HTTP_REQUEST_FILE, options);
1590         fclose(result);
1591
1592         if (ret == HTTP_OK && finalize_object_file(tmpfile.buf, filename))
1593                 ret = HTTP_ERROR;
1594 cleanup:
1595         strbuf_release(&tmpfile);
1596         return ret;
1597 }
1598
1599 int http_fetch_ref(const char *base, struct ref *ref)
1600 {
1601         struct http_get_options options = {0};
1602         char *url;
1603         struct strbuf buffer = STRBUF_INIT;
1604         int ret = -1;
1605
1606         options.no_cache = 1;
1607
1608         url = quote_ref_url(base, ref->name);
1609         if (http_get_strbuf(url, &buffer, &options) == HTTP_OK) {
1610                 strbuf_rtrim(&buffer);
1611                 if (buffer.len == 40)
1612                         ret = get_oid_hex(buffer.buf, &ref->old_oid);
1613                 else if (starts_with(buffer.buf, "ref: ")) {
1614                         ref->symref = xstrdup(buffer.buf + 5);
1615                         ret = 0;
1616                 }
1617         }
1618
1619         strbuf_release(&buffer);
1620         free(url);
1621         return ret;
1622 }
1623
1624 /* Helpers for fetching packs */
1625 static char *fetch_pack_index(unsigned char *sha1, const char *base_url)
1626 {
1627         char *url, *tmp;
1628         struct strbuf buf = STRBUF_INIT;
1629
1630         if (http_is_verbose)
1631                 fprintf(stderr, "Getting index for pack %s\n", sha1_to_hex(sha1));
1632
1633         end_url_with_slash(&buf, base_url);
1634         strbuf_addf(&buf, "objects/pack/pack-%s.idx", sha1_to_hex(sha1));
1635         url = strbuf_detach(&buf, NULL);
1636
1637         strbuf_addf(&buf, "%s.temp", sha1_pack_index_name(sha1));
1638         tmp = strbuf_detach(&buf, NULL);
1639
1640         if (http_get_file(url, tmp, NULL) != HTTP_OK) {
1641                 error("Unable to get pack index %s", url);
1642                 free(tmp);
1643                 tmp = NULL;
1644         }
1645
1646         free(url);
1647         return tmp;
1648 }
1649
1650 static int fetch_and_setup_pack_index(struct packed_git **packs_head,
1651         unsigned char *sha1, const char *base_url)
1652 {
1653         struct packed_git *new_pack;
1654         char *tmp_idx = NULL;
1655         int ret;
1656
1657         if (has_pack_index(sha1)) {
1658                 new_pack = parse_pack_index(sha1, sha1_pack_index_name(sha1));
1659                 if (!new_pack)
1660                         return -1; /* parse_pack_index() already issued error message */
1661                 goto add_pack;
1662         }
1663
1664         tmp_idx = fetch_pack_index(sha1, base_url);
1665         if (!tmp_idx)
1666                 return -1;
1667
1668         new_pack = parse_pack_index(sha1, tmp_idx);
1669         if (!new_pack) {
1670                 unlink(tmp_idx);
1671                 free(tmp_idx);
1672
1673                 return -1; /* parse_pack_index() already issued error message */
1674         }
1675
1676         ret = verify_pack_index(new_pack);
1677         if (!ret) {
1678                 close_pack_index(new_pack);
1679                 ret = finalize_object_file(tmp_idx, sha1_pack_index_name(sha1));
1680         }
1681         free(tmp_idx);
1682         if (ret)
1683                 return -1;
1684
1685 add_pack:
1686         new_pack->next = *packs_head;
1687         *packs_head = new_pack;
1688         return 0;
1689 }
1690
1691 int http_get_info_packs(const char *base_url, struct packed_git **packs_head)
1692 {
1693         struct http_get_options options = {0};
1694         int ret = 0, i = 0;
1695         char *url, *data;
1696         struct strbuf buf = STRBUF_INIT;
1697         unsigned char sha1[20];
1698
1699         end_url_with_slash(&buf, base_url);
1700         strbuf_addstr(&buf, "objects/info/packs");
1701         url = strbuf_detach(&buf, NULL);
1702
1703         options.no_cache = 1;
1704         ret = http_get_strbuf(url, &buf, &options);
1705         if (ret != HTTP_OK)
1706                 goto cleanup;
1707
1708         data = buf.buf;
1709         while (i < buf.len) {
1710                 switch (data[i]) {
1711                 case 'P':
1712                         i++;
1713                         if (i + 52 <= buf.len &&
1714                             starts_with(data + i, " pack-") &&
1715                             starts_with(data + i + 46, ".pack\n")) {
1716                                 get_sha1_hex(data + i + 6, sha1);
1717                                 fetch_and_setup_pack_index(packs_head, sha1,
1718                                                       base_url);
1719                                 i += 51;
1720                                 break;
1721                         }
1722                 default:
1723                         while (i < buf.len && data[i] != '\n')
1724                                 i++;
1725                 }
1726                 i++;
1727         }
1728
1729 cleanup:
1730         free(url);
1731         return ret;
1732 }
1733
1734 void release_http_pack_request(struct http_pack_request *preq)
1735 {
1736         if (preq->packfile != NULL) {
1737                 fclose(preq->packfile);
1738                 preq->packfile = NULL;
1739         }
1740         preq->slot = NULL;
1741         free(preq->url);
1742         free(preq);
1743 }
1744
1745 int finish_http_pack_request(struct http_pack_request *preq)
1746 {
1747         struct packed_git **lst;
1748         struct packed_git *p = preq->target;
1749         char *tmp_idx;
1750         size_t len;
1751         struct child_process ip = CHILD_PROCESS_INIT;
1752         const char *ip_argv[8];
1753
1754         close_pack_index(p);
1755
1756         fclose(preq->packfile);
1757         preq->packfile = NULL;
1758
1759         lst = preq->lst;
1760         while (*lst != p)
1761                 lst = &((*lst)->next);
1762         *lst = (*lst)->next;
1763
1764         if (!strip_suffix(preq->tmpfile, ".pack.temp", &len))
1765                 die("BUG: pack tmpfile does not end in .pack.temp?");
1766         tmp_idx = xstrfmt("%.*s.idx.temp", (int)len, preq->tmpfile);
1767
1768         ip_argv[0] = "index-pack";
1769         ip_argv[1] = "-o";
1770         ip_argv[2] = tmp_idx;
1771         ip_argv[3] = preq->tmpfile;
1772         ip_argv[4] = NULL;
1773
1774         ip.argv = ip_argv;
1775         ip.git_cmd = 1;
1776         ip.no_stdin = 1;
1777         ip.no_stdout = 1;
1778
1779         if (run_command(&ip)) {
1780                 unlink(preq->tmpfile);
1781                 unlink(tmp_idx);
1782                 free(tmp_idx);
1783                 return -1;
1784         }
1785
1786         unlink(sha1_pack_index_name(p->sha1));
1787
1788         if (finalize_object_file(preq->tmpfile, sha1_pack_name(p->sha1))
1789          || finalize_object_file(tmp_idx, sha1_pack_index_name(p->sha1))) {
1790                 free(tmp_idx);
1791                 return -1;
1792         }
1793
1794         install_packed_git(p);
1795         free(tmp_idx);
1796         return 0;
1797 }
1798
1799 struct http_pack_request *new_http_pack_request(
1800         struct packed_git *target, const char *base_url)
1801 {
1802         off_t prev_posn = 0;
1803         struct strbuf buf = STRBUF_INIT;
1804         struct http_pack_request *preq;
1805
1806         preq = xcalloc(1, sizeof(*preq));
1807         preq->target = target;
1808
1809         end_url_with_slash(&buf, base_url);
1810         strbuf_addf(&buf, "objects/pack/pack-%s.pack",
1811                 sha1_to_hex(target->sha1));
1812         preq->url = strbuf_detach(&buf, NULL);
1813
1814         snprintf(preq->tmpfile, sizeof(preq->tmpfile), "%s.temp",
1815                 sha1_pack_name(target->sha1));
1816         preq->packfile = fopen(preq->tmpfile, "a");
1817         if (!preq->packfile) {
1818                 error("Unable to open local file %s for pack",
1819                       preq->tmpfile);
1820                 goto abort;
1821         }
1822
1823         preq->slot = get_active_slot();
1824         curl_easy_setopt(preq->slot->curl, CURLOPT_FILE, preq->packfile);
1825         curl_easy_setopt(preq->slot->curl, CURLOPT_WRITEFUNCTION, fwrite);
1826         curl_easy_setopt(preq->slot->curl, CURLOPT_URL, preq->url);
1827         curl_easy_setopt(preq->slot->curl, CURLOPT_HTTPHEADER,
1828                 no_pragma_header);
1829
1830         /*
1831          * If there is data present from a previous transfer attempt,
1832          * resume where it left off
1833          */
1834         prev_posn = ftello(preq->packfile);
1835         if (prev_posn>0) {
1836                 if (http_is_verbose)
1837                         fprintf(stderr,
1838                                 "Resuming fetch of pack %s at byte %"PRIuMAX"\n",
1839                                 sha1_to_hex(target->sha1), (uintmax_t)prev_posn);
1840                 http_opt_request_remainder(preq->slot->curl, prev_posn);
1841         }
1842
1843         return preq;
1844
1845 abort:
1846         free(preq->url);
1847         free(preq);
1848         return NULL;
1849 }
1850
1851 /* Helpers for fetching objects (loose) */
1852 static size_t fwrite_sha1_file(char *ptr, size_t eltsize, size_t nmemb,
1853                                void *data)
1854 {
1855         unsigned char expn[4096];
1856         size_t size = eltsize * nmemb;
1857         int posn = 0;
1858         struct http_object_request *freq =
1859                 (struct http_object_request *)data;
1860         do {
1861                 ssize_t retval = xwrite(freq->localfile,
1862                                         (char *) ptr + posn, size - posn);
1863                 if (retval < 0)
1864                         return posn;
1865                 posn += retval;
1866         } while (posn < size);
1867
1868         freq->stream.avail_in = size;
1869         freq->stream.next_in = (void *)ptr;
1870         do {
1871                 freq->stream.next_out = expn;
1872                 freq->stream.avail_out = sizeof(expn);
1873                 freq->zret = git_inflate(&freq->stream, Z_SYNC_FLUSH);
1874                 git_SHA1_Update(&freq->c, expn,
1875                                 sizeof(expn) - freq->stream.avail_out);
1876         } while (freq->stream.avail_in && freq->zret == Z_OK);
1877         return size;
1878 }
1879
1880 struct http_object_request *new_http_object_request(const char *base_url,
1881         unsigned char *sha1)
1882 {
1883         char *hex = sha1_to_hex(sha1);
1884         const char *filename;
1885         char prevfile[PATH_MAX];
1886         int prevlocal;
1887         char prev_buf[PREV_BUF_SIZE];
1888         ssize_t prev_read = 0;
1889         off_t prev_posn = 0;
1890         struct http_object_request *freq;
1891
1892         freq = xcalloc(1, sizeof(*freq));
1893         hashcpy(freq->sha1, sha1);
1894         freq->localfile = -1;
1895
1896         filename = sha1_file_name(sha1);
1897         snprintf(freq->tmpfile, sizeof(freq->tmpfile),
1898                  "%s.temp", filename);
1899
1900         snprintf(prevfile, sizeof(prevfile), "%s.prev", filename);
1901         unlink_or_warn(prevfile);
1902         rename(freq->tmpfile, prevfile);
1903         unlink_or_warn(freq->tmpfile);
1904
1905         if (freq->localfile != -1)
1906                 error("fd leakage in start: %d", freq->localfile);
1907         freq->localfile = open(freq->tmpfile,
1908                                O_WRONLY | O_CREAT | O_EXCL, 0666);
1909         /*
1910          * This could have failed due to the "lazy directory creation";
1911          * try to mkdir the last path component.
1912          */
1913         if (freq->localfile < 0 && errno == ENOENT) {
1914                 char *dir = strrchr(freq->tmpfile, '/');
1915                 if (dir) {
1916                         *dir = 0;
1917                         mkdir(freq->tmpfile, 0777);
1918                         *dir = '/';
1919                 }
1920                 freq->localfile = open(freq->tmpfile,
1921                                        O_WRONLY | O_CREAT | O_EXCL, 0666);
1922         }
1923
1924         if (freq->localfile < 0) {
1925                 error_errno("Couldn't create temporary file %s", freq->tmpfile);
1926                 goto abort;
1927         }
1928
1929         git_inflate_init(&freq->stream);
1930
1931         git_SHA1_Init(&freq->c);
1932
1933         freq->url = get_remote_object_url(base_url, hex, 0);
1934
1935         /*
1936          * If a previous temp file is present, process what was already
1937          * fetched.
1938          */
1939         prevlocal = open(prevfile, O_RDONLY);
1940         if (prevlocal != -1) {
1941                 do {
1942                         prev_read = xread(prevlocal, prev_buf, PREV_BUF_SIZE);
1943                         if (prev_read>0) {
1944                                 if (fwrite_sha1_file(prev_buf,
1945                                                      1,
1946                                                      prev_read,
1947                                                      freq) == prev_read) {
1948                                         prev_posn += prev_read;
1949                                 } else {
1950                                         prev_read = -1;
1951                                 }
1952                         }
1953                 } while (prev_read > 0);
1954                 close(prevlocal);
1955         }
1956         unlink_or_warn(prevfile);
1957
1958         /*
1959          * Reset inflate/SHA1 if there was an error reading the previous temp
1960          * file; also rewind to the beginning of the local file.
1961          */
1962         if (prev_read == -1) {
1963                 memset(&freq->stream, 0, sizeof(freq->stream));
1964                 git_inflate_init(&freq->stream);
1965                 git_SHA1_Init(&freq->c);
1966                 if (prev_posn>0) {
1967                         prev_posn = 0;
1968                         lseek(freq->localfile, 0, SEEK_SET);
1969                         if (ftruncate(freq->localfile, 0) < 0) {
1970                                 error_errno("Couldn't truncate temporary file %s",
1971                                             freq->tmpfile);
1972                                 goto abort;
1973                         }
1974                 }
1975         }
1976
1977         freq->slot = get_active_slot();
1978
1979         curl_easy_setopt(freq->slot->curl, CURLOPT_FILE, freq);
1980         curl_easy_setopt(freq->slot->curl, CURLOPT_WRITEFUNCTION, fwrite_sha1_file);
1981         curl_easy_setopt(freq->slot->curl, CURLOPT_ERRORBUFFER, freq->errorstr);
1982         curl_easy_setopt(freq->slot->curl, CURLOPT_URL, freq->url);
1983         curl_easy_setopt(freq->slot->curl, CURLOPT_HTTPHEADER, no_pragma_header);
1984
1985         /*
1986          * If we have successfully processed data from a previous fetch
1987          * attempt, only fetch the data we don't already have.
1988          */
1989         if (prev_posn>0) {
1990                 if (http_is_verbose)
1991                         fprintf(stderr,
1992                                 "Resuming fetch of object %s at byte %"PRIuMAX"\n",
1993                                 hex, (uintmax_t)prev_posn);
1994                 http_opt_request_remainder(freq->slot->curl, prev_posn);
1995         }
1996
1997         return freq;
1998
1999 abort:
2000         free(freq->url);
2001         free(freq);
2002         return NULL;
2003 }
2004
2005 void process_http_object_request(struct http_object_request *freq)
2006 {
2007         if (freq->slot == NULL)
2008                 return;
2009         freq->curl_result = freq->slot->curl_result;
2010         freq->http_code = freq->slot->http_code;
2011         freq->slot = NULL;
2012 }
2013
2014 int finish_http_object_request(struct http_object_request *freq)
2015 {
2016         struct stat st;
2017
2018         close(freq->localfile);
2019         freq->localfile = -1;
2020
2021         process_http_object_request(freq);
2022
2023         if (freq->http_code == 416) {
2024                 warning("requested range invalid; we may already have all the data.");
2025         } else if (freq->curl_result != CURLE_OK) {
2026                 if (stat(freq->tmpfile, &st) == 0)
2027                         if (st.st_size == 0)
2028                                 unlink_or_warn(freq->tmpfile);
2029                 return -1;
2030         }
2031
2032         git_inflate_end(&freq->stream);
2033         git_SHA1_Final(freq->real_sha1, &freq->c);
2034         if (freq->zret != Z_STREAM_END) {
2035                 unlink_or_warn(freq->tmpfile);
2036                 return -1;
2037         }
2038         if (hashcmp(freq->sha1, freq->real_sha1)) {
2039                 unlink_or_warn(freq->tmpfile);
2040                 return -1;
2041         }
2042         freq->rename =
2043                 finalize_object_file(freq->tmpfile, sha1_file_name(freq->sha1));
2044
2045         return freq->rename;
2046 }
2047
2048 void abort_http_object_request(struct http_object_request *freq)
2049 {
2050         unlink_or_warn(freq->tmpfile);
2051
2052         release_http_object_request(freq);
2053 }
2054
2055 void release_http_object_request(struct http_object_request *freq)
2056 {
2057         if (freq->localfile != -1) {
2058                 close(freq->localfile);
2059                 freq->localfile = -1;
2060         }
2061         if (freq->url != NULL) {
2062                 free(freq->url);
2063                 freq->url = NULL;
2064         }
2065         if (freq->slot != NULL) {
2066                 freq->slot->callback_func = NULL;
2067                 freq->slot->callback_data = NULL;
2068                 release_active_slot(freq->slot);
2069                 freq->slot = NULL;
2070         }
2071 }